Electronics and photonics

In this section, the potential application for amyloid fibrils and other selfassembling fibrous protein structures are outlined. These include potential uses in electronics and photonics presented in Section 4.1, uses as platforms for the immobilization of enzymes and biosensors presented in Section 4.2, and uses as biocompatible materials presented in Section 4.3. Each of these applications makes use of the ability of polypeptides to self-assemble and form nanostructured materials, a process that can occur under aqueous conditions. These applications also seek to exploit the favorable properties of fibrils such as strength and durability, the ability to arrange ligands on a nanoscale, and their potential biocompatibility arising from the natural materials used for assembly. 

Another approach toward fibrillar nanowires has been taken by Baldwin and colleagues (2006), who assembled a porphyrin binding protein onto the surface of an amyloid fibril. This binding protein could incorporate heme to form a functional b-type cytochrome. These fibrils could be developed to create wires for electron transfer, similar to structures observed in nature that consist of chains of heme molecules. 

Other inorganic materials have been assembled on a wide range of selfassembling protein structures. Many of these studies have sought to mimic nature, which can create a vast range of templated inorganic structures. 

Copper has been immobilized on glycylglycine bolaamphiphile peptide nanotubes that display histidine residues, and paramagnetic gadolinium, a magnetic resonance image contrast agent, has been immobilized on nanofibers produced from peptide amphiphiles (see Gazit, 2007 and references therein). 

The polycylic fluorphore fluorene has also been assembled on the outside of fibrils constructed from the amyloidogenic TTR105-115 peptide (Channon et al., 2008). The fluroene unit has the ability to drive self-assembly. However, in this case the fluorene unit was attached to the TTR105-115 sequence which was used to drive fibril formation so that the fluorene unit was displayed on the fibril surface. Channon observed the transfer of 

---

Madey T E 1986 Electron- and photon-stimulated desorption probes of structure and bonding at surfaces Science 234 316... 

McDaniei E W 1989 Atomic Collisions Electron and Photon Projectiles (New York Wiiey)... 

As we have seen, the electron is the easiest probe to make surface sensitive. For that reason, a number of hybrid teclmiques have been designed that combine the virtues of electrons and of other probes. In particular, electrons and photons (x-rays) have been used together in teclmiques like PD [10] and SEXAFS (or EXAFS, which is the high-energy limit of XAES) [2, Hj. Both of these rely on diffraction by electrons, which have been excited by photons. In the case of PD, the electrons themselves are detected after emission out of the surface, limiting the depth of sampling to that given by the electron mean free path. 

Electrons and photons do not impact molecules or atoms. They interact with them in ways that result in various electronic excitations, including ionization. For this reason it is recommended that the terms electron impact and photon impact be avoided. 

This article focuses primarily on the properties of the most extensively studied III—V and II—VI compound semiconductors and is presented in five sections (/) a brief summary of the physical (mechanical and electrical) properties of the 2incblende cubic semiconductors (2) a description of the metal organic chemical vapor deposition (MOCVD) process. MOCVD is the preferred technology for the commercial growth of most heteroepitaxial semiconductor material (J) the physics and (4) apphcations of electronic and photonic devices and (5) the fabrication process technology in use to create both electronic and photonic devices and circuits. 

Plasma is a state of matter consisting of neutral excited radicals and ionic particles or fragments of molecules and also comprising electrons and photons. If a solid... 

There are two possible cases for the wavefunction of a system of identical fundamental particles such as electrons and photons. These are the symmetric and the antisymmetric cases. Experimental evidence shows that for fermions such as electrons and other particles of half integer spin the wavefunction must be anti-symmetric with respect to the interchange of particle labels. This... 

Jauch, J. M., and Rohrlich, F., Theory of Electrons and Photons, Appendix A2, Addison-Wesley, Cambridge, Mass., 1954. 

Kulander KC, Schafer KJ (1996) Time-Dependent Calculations of Electron and Photon Emission from an Atom in an Intense Laser Field 86 149-172 Kiinzel FM, see Buchler JW (1995) 84 1-70 Kurad D, see also Tytko KH (1999) 93 1-64 Kustin K, see Epstein IR (1984) 56 1-33... 

Jensen, K. F., Micro-reaction engineering applications of reaction engineering to processing of electronic and photonic materials, Chem. Eng. Sci., 42, 923-958 (1987). 

Quantum Mechanical Simulations of Polymers for Molecular Electronics and Photonics... 

The electronic and photonic properties of the arylated TEEs were investigated, with a special emphasis on the effects caused by degree and pattern of... 

It is highly likely that by the second decade of the new millennium silicon-based computing will have reached fundamental technological or physical limits. Computers will therefore be based on substrates that exhibit superior performance characteristics. One possibility is the photon. Optoelectronic devices, which use substrates such as gallium arsenide, permit the interconversion of electrons and photons. Hybrid computers, which may already be available commercially by 2010, would use silicon for computation and photons for data transfer. The coherent modulation of very-high-frequency light beams enables many high-capacity... 

C07-0118. Neutrons, like electrons and photons, are particle-waves whose diffraction patterns can be used to determine the structures of molecules. Calculate the kinetic energy of a neutron with a wavelength of 75 pm. 

Wong CP (1993) Polymers for electronic and photonic applications. Academic Press, New York... 

The electron and photon angular momentum projections, m, v, and the recoil direction, k, appearing in Eq. (A.3) are defined in the molecular frame, but our... 

Figure 1.7 Schematics of simultaneous incoming probability of electrons and photons for (a) continuous mode and (b) pulsed mode.

H. S. Nalwa, Ed., Handbook of Advanced Electronic and Photonic Materials and Devices. Academic Press, Boston, 2000. 

New natural polymers based on synthesis from renewable resources, improved recyclability based on retrosynthesis to reusable precursors, and molecular suicide switches to initiate biodegradation on demand are the exciting areas in polymer science. In the area of biomolecular materials, new materials for implants with improved durability and biocompatibility, light-harvesting materials based on biomimicry of photosynthetic systems, and biosensors for analysis and artificial enzymes for bioremediation will present the breakthrough opportunities. Finally, in the field of electronics and photonics, the new challenges are molecular switches, transistors, and other electronic components molecular photoad-dressable memory devices and ferroelectrics and ferromagnets based on nonmetals. 

Shyh Wang, Principles and Characteristics of Integratable Active and Passive Optical Devices Shlomo Margalit and Amnon Yariv, Integrated Electronic and Photonic Devices Takaaki Mukai, Yoshihisa Yamamoto, and Tatsuya Kimura, Optical Amplification by Semiconductor Lasers... 

Zhong, Z. Qian, F. Wang, D. Lieber, C. M. 2003. Synthesis of p-type gallium nitride nanowires for electronic and photonic nanodevices. Nano Lett. 3 343-346. 

McAlpine, M. C. Friedman, R. S. Lieber, C. M. 2005. High-performance nanowire electronics and photonics and nanoscale patterning on flexible plastic substrates. Proc. IEEE 93 1357-1363. 

The most probable fate of a photon with an energy higher than the binding energy of an encountered electron is photoelectric absorption, in which the photon transfers its energy to the electron and photon existence ends. As with ionization from any process, secondary radiations initiated by the photoelectron produce additional excitation of orbital electrons. 

---